cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-16 of 16 results.

A265497 Numbers n such that n*2^127 - 1 is prime.

Original entry on oeis.org

1, 103, 190, 289, 460, 483, 511, 534, 651, 793, 820, 880, 901, 939, 945, 958, 1045, 1168, 1195, 1198, 1216, 1374, 1408, 1479, 1489, 1500, 1521, 1534, 1539, 1569, 1599, 1623, 1630, 1671, 1678, 1875, 1938, 1939, 1963, 1996, 2028, 2136, 2140, 2166, 2179, 2289
Offset: 1

Views

Author

Vardan Semerjyan, Dec 09 2015

Keywords

Comments

The exponent of 2 in the expression, 127, is a Mersenne exponent.

Examples

			n = 1 is a term since 2^127 - 1 is prime (the 12th Mersenne prime).

Crossrefs

Cf. A000043, A001348, A005122.

Programs

  • MATLAB
    if isprime(n*2^127-1)
disp(n)
end
  • Magma
    [n: n in [1..3*10^3] |IsPrime(n*2^127-1)]; // Vincenzo Librandi, Dec 10 2015
  • Mathematica
    Select[Range@ 2560, PrimeQ[# 2^127 - 1] &] (* Michael De Vlieger, Dec 09 2015 *)
  • PARI
    is(n)=ispseudoprime(n*2^127 - 1) \\ Anders Hellström, Dec 09 2015

A265503 Numbers n such that n*2^2203 - 1 is prime.

Original entry on oeis.org

1, 13, 553, 861, 1983, 2065, 2403, 4371, 6226, 6553, 6580, 10128, 10998, 11193, 12411, 12598, 12909, 13056, 13194, 13399, 14589, 15829, 18429, 18436, 19315, 19900, 21574, 23599, 24006, 24024, 24415, 25704, 27225, 27651, 28689, 29461, 29805, 29868, 31143, 31186, 32674, 33706, 34306, 35016, 36118
Offset: 1

Views

Author

Vardan Semerjyan, Dec 09 2015

Keywords

Comments

The exponent of 2 in the expression, 2203, is a Mersenne exponent.

Examples

			n = 1 is a term since 2^2203 - 1 is prime (the 16th Mersenne prime).

Crossrefs

Cf. A000043, A001348, A005122.

Programs

  • MATLAB
    if isprime(n*2^2203-1)
disp(n)
end
  • Magma
    [n: n in [1..7*10^3] |IsPrime(n*2^2203-1)]; // Vincenzo Librandi, Dec 10 2015
  • Mathematica
    Select[Range@ 36200, PrimeQ[# 2^2203 - 1] &] (* Michael De Vlieger, Dec 09 2015 *)
  • PARI
    is(n)=ispseudoprime(n*2^2203-1) \\ Anders Hellström, Dec 09 2015

Extensions

More terms from Michael De Vlieger, Dec 09 2015

A265504 Numbers n such that n*2^2281 - 1 is prime.

Original entry on oeis.org

1, 1144, 4027, 7485, 9039, 9940, 11286, 11781, 13095, 13236, 13869, 14124, 14764, 16630, 18075, 18795, 19284, 20797, 21436, 22696, 23904, 25297, 25419, 27391, 27564, 28146, 28392, 29865, 30624, 31087, 31137, 31369, 33286, 33724, 33741, 34609, 34837, 35034, 37047, 37075, 39564, 39910, 41181
Offset: 1

Views

Author

Vardan Semerjyan, Dec 09 2015

Keywords

Comments

The exponent of 2 in the expression, 2281, is a Mersenne exponent.
All large values of n correspond to pseudoprimes whose primality needs to be verified.

Examples

			n = 1 is a term since 2^2281 - 1 is prime (the 17th Mersenne prime).

Crossrefs

Cf. A000043, A001348, A005122.

Programs

  • MATLAB
    if isprime(n*2^2281-1)
disp(n)
end
  • Magma
    [n: n in [1..10^4] |IsPrime(n*2^2281-1)]; // Vincenzo Librandi, Jan 12 2016
  • Mathematica
    Select[Range[10^4], PrimeQ[2^2281 # - 1] &] (* Vincenzo Librandi, Jan 12 2016 *)
  • PARI
    is(n)=ispseudoprime(n*2^2281 - 1) \\ Anders Hellström, Dec 16 2015

Extensions

More terms from Soumadeep Ghosh, Feb 14 2016

A265498 Numbers n such that n*2^521 - 1 is prime.

Original entry on oeis.org

1, 1362, 1756, 1905, 2337, 2707, 2902, 2997, 3487, 3492, 3787, 3879, 4045, 4266, 4374, 4680, 5106, 5691, 5766, 6321, 6352, 6585, 6819, 7056, 7099, 7162, 7470, 7627, 8055, 8061, 8121, 8499, 8511, 8785, 8865, 9432, 9636, 9876, 10116, 10389, 10629, 10752, 11262
Offset: 1

Views

Author

Vardan Semerjyan, Dec 09 2015

Keywords

Comments

The exponent of 2 in the expression, 521, is a Mersenne exponent.

Examples

			n = 1 is a term since 2^521-1 is prime (13th Mersenne prime).

Crossrefs

Cf. A000043, A001348, A005122.

Programs

  • MATLAB
    if isprime(n*2^521-1)
disp(n)
end
  • Magma
    [n: n in [1..2*10^4] |IsPrime(n*2^521-1)]; // Vincenzo Librandi, Dec 10 2015
  • Mathematica
    Select[Range@ 12050, PrimeQ[# 2^521 - 1] &] (* Michael De Vlieger, Dec 09 2015 *)
  • PARI
    is(n) = ispseudoprime(n*2^521 - 1); \\ Altug Alkan, Dec 10 2015

A265499 Numbers n such that n*2^607 - 1 is prime.

Original entry on oeis.org

1, 226, 273, 544, 675, 961, 1380, 1968, 2155, 2193, 2596, 3481, 3774, 4074, 4513, 4674, 4866, 4899, 5004, 5418, 5421, 5536, 5815, 5949, 6159, 6249, 6390, 6523, 6526, 6543, 7230, 7281, 7645, 7699, 7968, 8473, 8518, 8724, 8763, 8871, 9519, 9780, 9805
Offset: 1

Views

Author

Vardan Semerjyan, Dec 09 2015

Keywords

Comments

The exponent of 2 in the expression, 607, is a Mersenne exponent.

Examples

			n = 1 is a term since 2^607 - 1 is prime (the 14th Mersenne prime).

Crossrefs

Cf. A000043, A001348, A005122.

Programs

  • MATLAB
    if isprime(n*2^607-1)
disp(n)
end
  • Magma
    [n: n in [1..2*10^4] |IsPrime(n*2^607-1)]; // Vincenzo Librandi, Dec 10 2015
  • Mathematica
    Select[Range@ 12250, PrimeQ[# 2^607 - 1] &] (* Michael De Vlieger, Dec 09 2015 *)
  • PARI
    is(n)=ispseudoprime(n*2^607 - 1) \\ Anders Hellström, Dec 09 2015

A265505 Numbers n such that n*2^107 - 1 is prime.

Original entry on oeis.org

1, 25, 36, 81, 246, 273, 358, 378, 595, 658, 684, 703, 706, 739, 759, 883, 909, 958, 963, 970, 991, 1014, 1054, 1138, 1189, 1200, 1209, 1356, 1359, 1476, 1488, 1534, 1554, 1590, 1594, 1684, 1695, 1719, 1785, 1791, 1858, 1929, 2008, 2094, 2103, 2115, 2146, 2224, 2229, 2266, 2278, 2283, 2313, 2325, 2380, 2388, 2401
Offset: 1

Views

Author

Vardan Semerjyan, Dec 09 2015

Keywords

Comments

The exponent of 2 in the expression, 107, is a Mersenne exponent.

Examples

			n = 1 is a term since 2^107 - 1 is prime (the 11th Mersenne prime).

Crossrefs

Cf. A000043, A001348, A005122, A265497, A265502, A265503, A265504.

Programs

  • MATLAB
    if isprime(n*2^107-1)
disp(n)
end
  • Mathematica
    Select[Range@ 2401, PrimeQ[# 2^107 - 1] &] (* Michael De Vlieger, Dec 16 2015 *)
  • PARI
    is(n)=ispseudoprime(n*2^107- 1) \\ Anders Hellström, Dec 16 2015
Previous Showing 11-16 of 16 results.

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